The Claim

In resistance-trained males, daily supplementation with 200 mg of glutathione and 2 g of L-citrulline for 4 weeks during resistance training is associated with a statistically significant increase in lean mass compared to placebo, though this effect is not sustained at 8 weeks.

Source: Eight weeks of resistance training in conjunction with glutathione and L-Citrulline supplementation increases lean mass and has no adverse effects on blood clinical safety markers in resistance-trained males

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
63score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

In men who regularly lift weights, taking 200 mg of glutathione and 2 g of L-citrulline daily for 4 weeks along with training is linked to a measurable increase in lean body mass compared to a placebo, but this increase does not remain after 8 weeks.

See the scientific wording

In resistance-trained males, daily supplementation with 200 mg of glutathione and 2 g of L-citrulline for 4 weeks during resistance training is associated with a statistically significant increase in lean mass compared to placebo, though this effect is not sustained at 8 weeks.

Why this might work

L-citrulline turns into arginine in the body, which boosts nitric oxide production. Glutathione protects this nitric oxide from breaking down and helps it last longer. The sustained nitric oxide activates a signaling chain that turns on muscle-building machinery, leading to more muscle protein being made and more lean mass accumulating during training.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Eight weeks of resistance training in conjunction with glutathione and L-Citrulline supplementation increases lean mass and has no adverse effects on blood clinical safety markers in resistance-trained males

    This study found that taking glutathione and L-citrulline pills while weight training helped men gain a little more muscle after 4 weeks, but that extra muscle didn’t stick around after 8 weeks — just like the claim said.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.